In sedentary humans, central arterial compliance decreases with advancing age even in healthy men and women. Reductions in arterial compliance are believed to contribute significantly to the pathophysiology of the age-related increase in cardiovascular disease, and, accordingly, have recently been identified as an independent risk factor. The general aim of this research project is to determine 1) whether a program of regular resistance (strength) exercise can eliminate or partially reverse the decline in arterial compliance in previously sedentary middle-aged and older adults, 2) if combined aerobic and resistance training intervention improves central arterial compliance in previously sedentary adults, 3) whether the postulated increases in arterial compliance are accompanied by favorable changes in arterial baroreflex sensitivity and vascular-ventricular coupling, and 4) if the improvements in arterial compliance are mediated, at least in part, by reductions in the cross-linking of arterial wall collagen and advanced glycation endproducts as well as by the polymorphisms in genes associated with arterial wall elastin and collagen. Groups of young, middle-aged, and older men and women will be studied at baseline and then at the end of 6 months of either resistance training or combined resistance and aerobic training conditions. Additionally, subjects completing the attention control condition will serve as a time control. Static and dynamic arterial compliance will be determined with a simultaneous application of high-resolution ultrasonography and carotid artery applanation tonometry. The present research project should provide new and clinically useful insight into the role of regular physical activity on dynamic arterial compliance and its autonomic nervous system-cardiovascular consequences in middle-aged and older adult humans. If our working hypotheses are supported by the results of the proposed study, the information could be used to base recommendations and guidelines for the further use of regular resistance exercise in the primary and secondary prevention of age-related decreases in arterial compliance. This is crucial considering the fact that older adults are at increased risks for developing cardiovascular disease as well as for experiencing functional disability associated with reduced muscle mass and strength (sarcopenia).